Not only this, it increases the storage of visceral body fat. Visceral fat is belly fat and is a risk factor for cardiovascular disease and Type 2 diabetes. Ghrelin levels decrease after we eat, normally for around three hours.

One study found that ghrelin release is higher in women just before ovulation, so if you’re ever-ravenous at this time of the month, ghrelin could be the reason.

In order to lose weight, it’s best if ghrelin levels remain low.

Some researchers believe leptin levels may be connected with ghrelin levels. Interestingly, fructose can increase ghrelin, as can lack of sleep.

High stress also increases ghrelin levels. It appears ghrelin may help guard against symptoms of stress-induced anxiety and depression.

Insulin

This hormone regulates the level of sugar in our blood.

It’s released when blood sugar levels rise after eating. Insulin activates special receptors which cause sugar to enter our cells where it’s used as energy.

If we’re constantly eating sugary foods, our blood sugar will climb high then plummet too low, a situation known as hypoglycaemia.

After a while, insulin receptors become deaf to the message, meaning sugar is not shunted into the cells.

Because the blood sugar stays high, the body keeps on pumping out insulin which therefore remains elevated.

This is termed ‘insulin resistance’, and if you suffer from this, it’s incredibly hard to lose weight.

In excess, insulin leads to weight gain.

One study gave insulin to diabetes patients. They gained an average 8.7kg over six months despite eating 300 calories less per day than prior to the study!

It appears insulin causes our body to lower its metabolic rate and burn fewer calories and may make the body resistant to burning off stored fat for energy.

It controls many bodily functions including our metabolic rate, in other words, the speed at which we produce energy and burn fat. If thyroxine production drops, the metabolism becomes sluggish and stored fat is burned more slowly. Problems can also occur if we can’t convert thyroxine to its active form.

Low thyroid function, known as hypothyroid, affects ten times as many women as men and is most common between the ages of 40 and 50.

Many thyroid disorders go undiagnosed and lead to fatigue and problems achieving weight loss.

Many factors can interfere with the functioning of our thyroid.

Stress reduces the number of thyroid hormones produced and blocks the conversion of thyroxine to its active form.

Mercury, leached into the blood from dental amalgams and found in tinned fish such as tuna, can lead to similar problems.

Fluoride, found in toothpaste and some water, has a similar chemical structure to iodine, meaning it can replace the iodine molecule in thyroxine, rendering it ineffective.

Goitrogens are chemicals found in certain foods which can interfere with thyroid function. Culprits include soya, millet and brassica vegetables like broccoli, brussels sprouts, cabbage, cauliflower and kale.

Caffeine can not only interfere with sleep and plays havoc with your blood sugar level, it also raises cortisol levels.

In one study caffeine intake equivalent to three cups of coffee while under mild stress was found to boost cortisol by about a quarter, and the effect lasted for three hours. Remember that tea, cola drinks and energy drinks also contain caffeine.

A blood sugar balancing diet can reverse insulin resistance and decrease cortisol levels, so it’s a vital component in any weight loss programme.

As a bonus, once your blood sugar levels are stable, you may find your sleep will improve, particularly if you tend to wake up at the same time each night because blood sugar crashes release adrenaline, which wakes you up.

Choose unprocessed, complex carbohydrates instead of simple sugars which release their energy slowly into the bloodstream to avoid insulin peaks and troughs.

An added benefit of including high-fibre foods in your diet is they make you feel fuller sooner.

Some fats don’t make you fat

Omega 3 Essential Fatty acids appear to help to lower insulin resistance and therefore help with weight loss.

Scientists have suggested they could also influence leptin resistance. These fats are found in oily fish, flax, pumpkin and chia seeds, and nuts like walnuts.